Missing render preview. No automatic re-render when changes are made, etc
If you're referring to the "update automatically" option under view menu of UV/image editor, which is also used to keep rendering results, this:



which says "update other affected window spaces automatically to reflect changes during interactive operations such as transform"

Imho that has nothing to do with re-rendering automatically. That, for sure, acts on UV editing: if enabled, e.g., other 3D views in "textured" mode are updated automatically while you're still transforming your UV map in that editor. Without it enabled, the update happen only after you commit the UV editing. It sort enables a realtime results preview while editing UV.

To get something similar to what you describe, you could get that effect using another Blender editor option:

instead of using this windows setup:



you could use "area duplication" options like:



obtaining a small separate window that you can set as "rendered" viewport shading (works both in Internal and Cycles, nowadays):



Now, in this way every little change in your objects is immediately reflected (re-rendered) in the small window. Hth.